Design of Minimal Waste Process for Levulinic and Formic Acids Production from Glucose by Using Choline Chloride Added Aluminum Chloride Catalyst System

A process for levulinic acid (LA) production from glucose with AICl(3) catalyst in choline chloride aqueous solution has been designed and numerically simulated. Energy and process economics were evaluated. This process minimized waste materials by recovering catalysts and the coproduct formic acid (FA), and utilizing humins as a heat source. Furfural was applied for the LA purification, and octanol and toluene were used as extracting agents for the FA purification process based on the solubility with water, distribution coefficient between water and LA or FA, and green chemistry perspective. The required energy for this process was determined in the case of the glucose feed rate of 100 kg/h and the reaction time of 90, 120, and 180 min based on the literature data. Minimum selling prices (MSPs) of products were calculated based on the capital and operation costs of the production of LA and FA with an internal rate of return of 6.1% in 20 years. It was found that the energy required in this process was 40.6-44.5 MJ/kg-LA (much less than that in conventional methods), and the MSP was 6.47-8.80 USD/kg (lower than the market price of LA). Part of the required energy (12.2-24.7%) can be supplied with a furnace, which combusts humins and accounts for 21% of the total capital cost. It is found that the installing of a humin furnace only affected 0.74-1.09% of the MSP, which should be economically feasible in a practical process. Overall, the reaction time in 90 min was the most preferable process in both energy requirements and economics.

Automated summary

The research focused on improving energy efficiency and economics of levulinic acid production by minimizing waste materials, recovering catalysts, and utilizing humins. Purification of levulinic acid and formic acid was achieved through the use of furfural and extracting agents.